The present invention relates to a device for attaching, and to a method for attaching, a dispenser member, such as a pump or a valve, to the neck of a receptacle containing a substance to be dispensed.
It is known that a dispenser or dispenser member can be attached or fixed to the neck of a receptacle by means of a collar or ring in a way that does not require crimping and thus facilitates assembly of the device.
In known techniques (e.g., U.S. Pat. No. 2,723,773 issued to E. Greene in 1955), a fixing ring or attaching ring of the xe2x80x9csnap-fasteningxe2x80x9d type is placed on the body of a dispenser member and is snap-fastened to the neck of the receptacle, generally by means of snap-fastening tabs provided for that purpose. A cup, hoop, or band is then engaged around the collar or ring to hold the collar or ring securely to the neck of the receptacle.
In order to have an inexpensive and simple assembly, it is typically necessary to effect both the snap-fastening of the ring and the engagement of the hoop mechanically by means of a single, automatic assembly machine. The assembly machine exerts sufficient force on the hoop so that the ring is first snap-fastened on the neck of the receptacle and so that the hoop is also subsequently fully engaged around the ring.
Conventional attachment devices suffer from certain drawbacks. In particular, when the force exerted on the hoop is not uniformly distributed around its periphery, there is a risk of the hoop being forced away from its vertical position in the assembly machine so that the hoop becomes cocked or slanted and engaged obliquely on the fixing ring, thereby preventing proper overall assembly.
An object of the present invention is to avoid that drawback by providing an attaching ring or fixing ring that ensures effective and reliable engagement with the hoop.
The present invention provides an attaching ring or a fixing ring for attaching or fixing a dispenser member on a neck of a receptacle containing a substance to be dispensed. The fixing ring is annular and comprises a bottom portion and a top portion. The bottom portion includes attaching means or fixing means for fixing the ring to the neck. The top portion includes an opening for the dispenser member as well as means for securing the dispenser member on the container neck.
The top portion further includes at least one guide wall element extending vertically parallel to the longitudinal axis of the dispenser member and around the periphery of the fixing ring substantially in line with the fixing means of the bottom portion. This guide wall element guides the hoop during installation and facilitates proper engagement of the components.
In a preferred embodiment of the ring, the fixing means are snap-fastening means. Most preferably, the snap-fastening means are in the form of tabs.
In the preferred embodiment of the ring, the guide wall elements form a continuous, guiding, annular crown.
The fixing ring is adapted to be threaded around, or otherwise mounted to, the head of a dispenser member. A fixing ring made in accordance with the invention also has the advantage of accommodating partial installation of a cup or hoop partway on the fixing ring which has been mounted to the dispenser member. The hoop can be disposed on the ring around the guide wall elements prior to being delivered to the customer. The customer then merely has to fill the receptacle with the chosen substance and place the subassembly or unit formed by the dispenser member, the fixing ring, and the hoop in the assembly machine. The assembly machine mounts the pre-assembled subassembly or unit on the receptacle to engage the fixing means with the receptacle neck and subsequently pushes the hoop down relative to the ring to effect final assembly of the hoop in a fully engaged position around the ring.
The guide wall elements effectively eliminate, or at least minimize, the likelihood of separation of the hoop from the fixing ring during delivery to the customer (e.g., when separation forces are imposed on the components due to vibration in transport). The guide wall elements also ensure that the hoop is correctly positioned for initial engagement by the assembly machine and for accommodating subsequent full engagement with the ring in the final assembly configuration.
Preferably, the guide wall elements have an outside diameter that is approximately equal to the inside diameter of the hoop, thereby enabling the hoop to be slidably engaged with the ring so that the frictional engagement prevents easy separation.
Another aspect of the invention provides a multi-component attaching device or fixing device for fixing a dispenser member to the neck of a receptacle containing a substance to be dispensed. In the preferred form, the multi-component device includes two components. The device includes an annular fixing ring provided with snap-fastening means designed to snap-fasten to the neck of the receptacle. The device also includes an annular hoop with an inside diameter substantially equal to the outside diameter of the fixing ring and which is adapted to be mounted on the fixing ring in a force fit (i.e., by means of a force fit, such as a press fit) to prevent the snap-fastening means from splaying apart.
The ring of the multi-component device comprises a bottom portion and a top portion. The bottom portion includes the snap-fastening means for snap-fastening to the receptacle neck. The top portion includes an opening for the dispenser member and means for holding the dispenser member securely to the neck. The top portion further includes at least one guide wall element extending vertically parallel to the longitudinal axis of the dispenser member around the periphery of the fixing ring and substantially in line with the snap-fastening means of the bottom portion.
To obtain effective assembly of the fixing ring and of the hoop with a single assembly machine, it is essential for the ring to be completely snap-fastened on the neck of the receptacle before the hoop is fully engaged with the ring in the final position.
Generally, this problem is solved by providing an initial friction fit between the ring and the hoop in an initial, non-final position wherein the force of the initial frictional engagement is greater than the force required to initially snap-fasten the ring on the neck of the receptacle.
By exerting enough force on the hoop, it is thus possible to first snap-fasten the ring on the neck of the receptacle, and subsequently move the hoop from its initial position completely down over the ring to a final position. However, as conventionally effected, this technique suffers from the drawback that the relative dimensions of the ring and of the hoop must be accurately defined so that the friction force between them is always the same.
Unfortunately, for manufacturing reasons, those dimensions are likely to vary somewhat, and as a result, proper assembly is not guaranteed. It is essential for the ring to snap-fasten before the hoop is positioned around snap-fastening means thereon, and that may not occur if the resistance to snap-fastening is too great or if the friction between the ring and the hoop is too small.
In a system described in German patent application No. P43 38 791.8, one or more outwardly projecting pins are provided on the outside circumference of the snap-fastening ring. The bottom of the hoop initially bears against them. When a downward force is applied to the hoop, the hoop and ring move down together in this pre-assembly configuration. The ring, while being driven downwardly by the hoop engaging the ring pins, is caused to snap-fasten onto the receptacle before the pins are broken or inwardly deformed by the effect of a subsequent greater installation force which allows the hoop to be moved down on the ring and fully engaged around the ring. That solves the problem of tolerance of the dimensions. However, such special rings can be difficult to mold, and that increases the cost of the device.
An object of one form of the present invention is to avoid the above-identified drawbacks by providing a snap-fastening ring and a hoop that are easy to mold, that can be assembled by a single assembly machine, and that facilitate effective assembly independently of dimensional tolerances, thereby making it possible significantly to reduce the manufacturing costs of a dispenser.
One form of the present invention therefore provides a further improved, multi-component fixing device for attaching or fixing a dispenser member to the neck of a container or other receptacle containing a substance to be dispensed. The device includes an annular fixing ring provided with snap-fastening means designed to snap-fasten to the neck of the receptacle.
The device also includes an annular hoop which has an inside diameter that is substantially equal to the outside diameter of the fixing ring. The hoop is adapted to be engaged in a force fit (i.e., by means of a force fit, such as a press fit) on the fixing ring to prevent the snap-fastening means from splaying apart.
The fixing ring comprises a bottom portion and a top portion. The bottom portion includes the snap-fastening means for engaging the neck. The top portion includes an opening for the dispenser member and means for holding it securely to the neck. The top portion further includes at least one guide wall element extending vertically parallel to the longitudinal axis of the dispenser member around the periphery of the fixing ring substantially in line with the snap-fastening means of the bottom portion.
The hoop has an annular side wall. The hoop includes at least one projection on the inside face of its side wall which extends vertically over at least a fraction of the height of the side wall. The inside diameter of the hoop at the projection is slightly less than the outside diameter of the fixing ring. Preferably, the projection is in the form of a rib. In one embodiment, the rib can be defined by the convex side of an indentation formed in the side wall.
For delivery purposes, the hoop can initially be pre-engaged partway on the ringxe2x80x94on the guide wall of the fixing ringxe2x80x94with the bottom end of the projection abutting the top end of the guide wall. During final assembly, the projection pushes against the guide wall of the ring, and the ring and the hoop are initially moved together to snap-fasten the ring on the neck of the receptacle before the hoop is subsequently moved down relative to the ring and positioned around the snap-fastening elements of the ring.
Preferably, the hoop includes a plurality of projections uniformly distributed around the inside face of the side wall of the hoop.
In a preferred form, the projection extends vertically from the top end of the hoop to a point situated more than halfway down the height of the hoop.
Optionally, the projection may have the form of an annular shoulder extending horizontally around the entire circumference of the hoop.
Preferably, the hoop is made of a material that is harder than that of the fixing ring. In a preferred form, the hoop is made of metal, and the fixing ring is made of a plastic material.
In another embodiment, the invention includes a particular type of a projection on the hoop of a multi-component fixing device for attaching or fixing a dispenser member to the neck of a receptacle containing a substance to be dispensed. The fixing device includes an annular fixing ring provided with snap-fastening means designed to snap-fasten to the neck of the receptacle.
The fixing device also includes an annular hoop which has an inside diameter that is substantially equal to the outside diameter of the fixing ring. The hoop is adapted to be engaged in a force fit with the fixing ring to prevent the snap-fastening means from splaying apart.
The fixing ring comprises a bottom portion and a top portion. The bottom portion includes the snap-fastening means for snap-fastening to the neck. The top portion includes an opening for the dispenser member and means for holding it securely to the neck. The top portion further includes at least one guide wall element extending vertically parallel to the longitudinal axis of the dispenser member around the periphery of the fixing ring substantially in line with the snap-fastening means of the bottom portion.
The hoop includes at least one projection on the inside face of its side wall. The projection extends obliquely over at least a fraction of the height of the side wall. The inside diameter of the hoop at the projection is slightly less than the outside diameter of the fixing ring.
Preferably, the projection is a rib. The rib may be defined by the convex side of an indentation formed in the hoop side wall.
The use of the obliquely oriented projection advantageously facilitates separation of the hoop (which is typically made of metal) from the fixing ring (which is typically made of a plastic material) by unscrewing the hoop. This is of particular advantage for selective recycling of the different component materials from which the dispenser is made.
The present invention also provides a method of attaching or fixing a dispenser member to the neck of a container or other receptacle containing a substance to be dispensed. The method comprises the following steps:
(1) placing an annular attaching ring or fixing ring on the dispenser member, the annular fixing ring being provided at one end with snap-fastening means and its opposite end with a guide wall extending in line with the snap-fastening means parallel to the longitudinal axis of the fixing ring;
(2) pre-engaging or partly engaging an annular hoop at an initial or first position on the guide wall of the fixing ring, the inside diameter of the hoop being substantially equal to the outside diameter of the fixing ring;
(3) placing a subassembly of the dispenser member, the fixing ring, and the hoop on the neck of the receptacle;
(4) exerting a first force F1 on the hoop which bears against the guide wall of the fixing ring and urges the fixing ring into further engagement with the neck of the receptacle, the snap-fastening means first splaying apart under the effect of the force F1 and subsequently snap-fastening to the neck of the receptacle as the ring moves with the hoop relative to the receptacle; and
(5) exerting on the hoop a second force F2 that is greater than the first force F1, the second force F2 being sufficient to cause the hoop to move relative to the fixing ring at a final position to further engage the fixing ring in a force fit with a portion of the hoop being located adjacent the snap-fastening means, the hoop thus preventing the snap-fastening means of the fixing ring from splaying apart.
The present invention also provides another form of a method of attaching or fixing a dispenser member to the neck of a container or other receptacle having a flange and containing a substance to be dispensed. The method comprises the following steps:
(1) placing an annular attaching ring or fixing ring on the dispenser member, the fixing ring being provided at one end with snap-fastening means and at its opposite end with a guide wall extending in line with the snap-fastening means parallel to the longitudinal axis of the fixing ring;
(2) pre-engaging or partly engaging an annular hoop at an initial or first position on the guide wall of the fixing ring, the inside diameter of the hoop being substantially equal to the outside diameter of the fixing ring and the hoop being provided on the inside face of its side wall with at least one projection extending along at least a fraction of the height of the side wall, the inside diameter of the hoop at the projection being slightly less than the outside diameter of the fixing ring, the hoop being partly engaged or pre-engaged on the guide wall in the position where the bottom end of the projection of the hoop bears against the top end of the guide wall of the fixing ring;
(3) placing a subassembly of the dispenser member, the fixing ring, and the hoop on the neck of the receptacle;
(4) exerting a first force F1 on the hoop which bears against the guide wall of the fixing ring via the bottom end of the projection and which pushes the fixing ring against the neck of the receptacle, the snap-fastening means first splaying part under the effect of the force F1 prior to snap-fastening to the flange of the neck of the receptacle; and
(5) exerting on the hoop a second force F2 greater than the first force F1, the second force F2 being sufficient to cause the hoop to move relative to the fixing ring to a final position so as to further engage the fixing ring in a force fit with a portion of the hoop being located adjacent the snap-fastening means, the hoop thereby preventing the snap-fastening means of the fixing ring from splaying apart.